Oil pump device

ABSTRACT

An oil pump device includes a motor, a pump, a pump cover, and a solenoid. The pump cover includes a discharge port, an intake opening through which oil is suctioned, a first discharge opening and a second discharge opening through which oil is discharged, a first oil passage that is a flow path between the first discharge opening and the discharge port, and a second oil passage that is a flow path between the second discharge opening and the discharge port. A solenoid valve of a solenoid is located on the second oil passage.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a U.S. national stage of PCT Application No. PCT/JP2018/009426, filed on Mar. 12, 2018, and priority under 35 U.S.C. § 119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No. 2017-057161, filed Mar. 23, 2017; the entire disclosures of each application are hereby incorporated herein by reference.

1. FIELD OF THE INVENTION

The present disclosure relates to an oil pump device.

2. BACKGROUND

In an automatic transmission (AT), which is a transmission mechanism of an automobile, power of an engine is transmitted to the transmission via oil. An oil pump and a solenoid valve are incorporated into the transmission. The oil pump is a pressure source that circulates oil inside the automatic transmission and generates hydraulic control operating pressure. The solenoid valve serves to adjust an amount of circulating oil.

Japanese Unexamined Patent Application Publication No. 2015-148310 discloses a system in which an individual oil pump and a solenoid valve are separately disposed in a control valve in which an oil passage which is an oil flow path is stretched.

However, in the system disclosed in Japanese Unexamined Patent Application Publication No. 2015-148310, since the individual oil pump and solenoid valve are separately disposed in the control valve, the system becomes large as a whole.

In addition, there is inconvenience in the related art that operations become unstable in a half-clutch state due to an oil vibration caused by a pressure variation of the oil pump. In order to solve this problem, raising the number of rotations of the pump rotor is conceivable. However, the oil flow amount increases if the number of rotations is simply raised, and thus it is hard to maintain pressure in the half-clutch state.

SUMMARY

Example embodiments of the present disclosure provide oil pump devices that each solve the inconvenience in operations in the half-clutch state and miniaturize the system.

An oil pump device of an example embodiment of the present disclosure includes a motor including a shaft that is disposed along a central axis, a rotor that rotates around the shaft, a stator that is disposed to face the rotor, and a housing that accommodates the rotor and the stator, and a pump including a pump rotor that rotates along with the shaft and sucks and discharges oil, and a pump housing that includes an accommodation portion that accommodates the pump rotor, in which the pump housing includes an intake opening through which the oil is suctioned, a discharge opening through which the oil is discharged, and a solenoid valve that is disposed between the discharge opening and the accommodation portion.

According to example embodiments of the present disclosure, it is possible to provide oil pump devices that each solve the inconvenience in operations in the half-clutch state and miniaturize the system.

The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an oil pump device according to a first example embodiment of the present disclosure.

FIG. 2 is a partial cross-sectional view illustrating the oil pump device according to the first example embodiment of the present disclosure.

FIG. 3 is a partial cross-sectional view illustrating main portions of the oil pump device according to the first example embodiment of the present disclosure.

FIG. 4 is a perspective view illustrating the inside of a pump cover portion.

FIG. 5 is a plan view illustrating an inside of the pump cover portion.

FIG. 6 is a partial cross-sectional view illustrating a flow of oil inside an oil pump.

FIG. 7 is a partial cross-sectional view illustrating main portions of an oil pump device according to a second example embodiment of the present disclosure.

DETAILED DESCRIPTION

Oil pump devices according to example embodiments of the present disclosure will be described below with reference to the drawings. In addition, the actual structures, and scales, reference numerals, and the like of each structure may differ in the following drawings to make it easier to understand each of the structures.

In addition, in the drawings, an XYZ coordinate systems is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z axis direction is a direction parallel to the axial direction of the central axis J illustrated in FIG. 2. The X axis direction is a direction parallel to the direction in which a busbar 64 illustrated in FIG. 2 extends, that is, a horizontal direction in FIG. 1. The Y axis direction is a direction orthogonal to both the X axis direction and the Z axis direction.

In addition, in the following description, the positive side of the Z axis direction (+Z side) will be denoted as a “front side” and the negative side of the Z axis direction (−Z side) will be denoted as a “rear side.” Further, the rear side and the front side are merely names used for description and do not limit actual positional relations and directions. In addition, unless specified otherwise, a direction parallel to the central axis J (the Z axis direction) will be denoted simply as an “axial direction,” a radial direction with respect to the central axis J will be denoted simply as a “radial direction,” and a circumferential direction with respect to the central axis J, that is, the direction around the central axis J (the θ direction), will be denoted simply as a “circumferential direction.”

Further, in the present specification, “extending in the axial direction” includes not only extending exactly in the axial direction (the Z axis direction) but also extending in a direction inclined in an angular range smaller than 45°. In addition, in the present specification, “extending in the radial direction” includes not only extending exactly in the radial direction, that is, extending in a direction perpendicular to the axial direction (the Z axis direction), but also extending in a direction inclined with respect to the radial direction in an angular range smaller than 45°.

First Example Embodiment <Overall Configuration>

FIG. 1 is a perspective view illustrating an oil pump device according to the present example embodiment.

The oil pump device 10 of the present example embodiment has a motor 20, a pump 30, a control circuit part 60, a pump cover portion 80, and a solenoid 90. Both the motor 20 and the pump 30 are provided inside a housing 21. The motor 20, the pump 30, and the pump cover portion 80 are provided in a row in the axial direction. The pump cover portion 80 has an intake opening 84, a first discharge opening 85, and a second discharge opening 86 serving as an inlet and outlets of oil.

FIG. 2 is a partial cross-sectional view illustrating the oil pump device according to the present example embodiment.

The motor 20 has a shaft 41 extending in the axial direction and supported to be rotatable with respect to the central axis J and causes the shaft 41 to rotate to drive the pump. The pump 30 is positioned on the front side (the +Z side) of the motor 20, is driven by the motor 20 via the shaft 41, and discharges oil. The control circuit part 60 is positioned on the rear side (the −Z side) of the motor 20 and controls driving of the motor 20. The pump cover portion 80 is positioned on the front side (the +Z side) of the pump 30 and has a main body accommodating the motor 20 and the pump 30 and each component of the solenoid 90 installed therein. The solenoid 90 detects pressure of oil circulating inside the pump 30 and adjusts an amount of oil.

Each of the constituent members will be described below in detail.

<Motor 20>

The motor 20 has the housing 21, a rotor 40, the shaft 41, a stator 50, a bearing part 55, and a busbar assembly 56 as illustrated in FIG. 2.

The motor 20 is, for example, an inner rotor-type motor, in which the rotor 40 is fixed to an outer circumferential surface of the shaft 41 and the stator 50 is positioned outward from the rotor 40 in the radial direction. In addition, the bearing part 55 is disposed outward from the shaft 41 in the radial direction on the rear side (the −Z side) of the rotor 40 and rotatably supports the shaft 41. The busbar assembly 56 is disposed outward from the bearing part 55 in the radial direction and fixed to the bearing part 55 in the radial direction. In addition, the busbar assembly 56 is electrically connected to the stator 50.

(Housing 21)

The housing 21 has a bottomed thin cylindrical shape as illustrated in FIG. 2 and accommodates the motor 20, the pump 30, and the control circuit part 60. As a material of the housing 21, for example, a zinc-aluminum-magnesium-based alloy, or the like may be used, and specifically, a molten zinc-aluminum-magnesium-alloy-plated steel sheet and strip may be used. The housing 21 has a bottom part 21 a, a control circuit holding part 21 b, a stator holding part 21 c, a pump body holding part 21 d, and flange parts 21 e and 21 f. The bottom part 21 a constitutes a bottomed portion. The control circuit holding part 21 b, the stator holding part 21 c, and the pump body holding part 21 d constitute a cylindrical side wall surface with respect to the central axis J. In the present example embodiment, the inner diameter of the control circuit holding part 21 b is larger than that of the stator holding part 21 c, and the inner diameter of the stator holding part 21 c is larger than that of the pump body holding part 21 d.

A control circuit case 61, which will be described below, is accommodated on an inner side of the control circuit holding part 21 b on the front side (the +Z side) of the bottom part 21 a. An outer surface of the stator 50, that is, an outer surface of a core back part 51, which will be described below, is fitted onto an inner surface of the stator holding part 21 c. Accordingly, the stator 50 is accommodated in the housing 21. An outer side surface of a pump body 31, which will be described below, is fitted onto an inner side surface of the pump body holding part 21 d. Accordingly, the pump body 31 is accommodated in the housing 21.

The flange part 21 e stretches outward in the radial direction from an end of the control circuit holding part 21 b on the front side (the +Z side). Meanwhile, the flange part 21 f stretches outward in the radial direction from an end of the stator holding part 21 c on the rear side (the −Z side).

The flange part 21 e and the flange part 21 f face each other and are fastened by a fastening means, which is not illustrated. Accordingly, the motor 20, the pump 30, and the control circuit part 60 are sealed and fixed inside the housing 21.

(Rotor 40)

The rotor 40 has a rotor core 43 and a rotor magnet 44. The rotor core 43 surrounds the shaft 41 in the direction around the axis (the 0 direction) and is fixed to the shaft 41. The rotor magnet 44 is fixed to an outer side surface of the rotor core 43 in the direction around the axis (the 0 direction). The rotor core 43 and the rotor magnet 44 rotate along with the shaft 41.

(Stator 50)

The stator 50 surrounds the rotor 40 in the direction around the axis (the 0 direction) and causes the rotor 40 to rotate around the central axis J. The stator 50 has a core back part 51, tooth parts 52, a coil 53, and an insulator (bobbin) 54.

The core back part 51 has a cylindrical shape concentric with the shaft 41. The tooth part 52 extends from an inner side surface of the core back part 51 toward the shaft 41. A plurality of tooth parts 52 are provided and are disposed at equal intervals in a circumferential direction of the inner side surface of the core back part 51. The coil 53 is provided in the vicinity of the insulator (bobbin) 54 and is formed by winding a conductive wire 53 a. The insulator (bobbin) 54 is installed in each of the tooth parts 52.

(Bearing Part 55)

The bearing part 55 is disposed on the rear side (the −Z side) of the rotor 40 and the stator 50 and supports the shaft 41. The bearing part 55 is held by the busbar assembly 56 outward in the circumferential direction. A shape, a structure, and the like of the bearing part 55 are not particularly limited, and any known bearing may also be used.

The busbar assembly 56 is electrically connected to an external power supply and the stator 50 and supplies currents to the stator 50.

<Control Circuit Part 60>

The control circuit part 60 is disposed on the rear side (the −Z side) of the motor 20 and controls driving of the motor 20.

The control circuit part 60 has the control circuit case 61, a control circuit 62, a power supply opening 63, a busbar 64, and a wiring member 65. The motor 20 is connected to an external power supply via the control circuit part 60.

The control circuit case 61 accommodates the control circuit 62.

The busbar 64 and the wiring member 65 extend to the +X side in the radial direction inside (the right side of the drawing) the control circuit case 61, and a tip of each of the components protrudes inside the power supply opening 63. The external power supply is electrically connected to the busbar 64 and the wiring member 65. Accordingly, a driving current is supplied to the coil 53 of the stator 50 and a rotation sensor (not illustrated) via the busbar 64 and the wiring member 65. The driving current supplied to the coil 53 is controlled according to, for example, a rotation position of the rotor 40 measured by the rotation sensor. When a driving current is supplied to the coil 53, a magnetic field is generated, and the magnetic field causes the rotor 40 to rotate. Through this operation, the motor 20 obtains a rotational driving force.

<Pump 30>

The pump 30 is provided on one side of the motor 20 in the axial direction, specifically on the front side (the +Z side) thereof. The pump 30 has the same rotational axis as the motor 20 and is driven by the motor 20 via the shaft 41. The pump 30 has a positive displacement pump that feeds oil by pressure as the volume of a sealed space (oil chamber) expands and contracts. For the positive displacement pump, for example, a trochoid pump may be used. The pump 30 has a pump body 31 and a pump rotor 35.

(Pump Body 31)

The pump body 31 is positioned on the front side (the +Z side) of the motor 20. The pump body 31 has a pump main body 31 b, a through hole 31 a that penetrates the inside of the pump main body 31 b in the axial direction of the central axis J, and a protrusion 31 c cylindrically protruding from the pump main body 31 b to the front side (the +Z side). An inner diameter of the protrusion 31 c is larger than that of the through hole 31 a. The protrusion 31 c and the pump main body 31 b constitute a recess 33 that is open to the pump cover portion 80 side. The through hole 31 a is open to the motor 20 side on the rear side (the −Z side) and open to the recess 33 on the front side (the +Z side). The through hole 31 a functions as a bearing member that receives insertion of the shaft 41 and rotatably supports the shaft 41. The recess 33 accommodates the pump rotor 35 and functions as a pump chamber (which will also be described as a pump chamber 33).

The pump body 31 is fixed into the pump body holding part 21 d on the front side (the +Z side) of the motor 20. An 0 ring 71 is provided between the outer circumferential surface of the pump main body 31 b and the inner circumferential surface of the pump body holding part 21 d in the radial direction. Accordingly, the space between the outer circumferential surface of the pump body 31 and the inner circumferential surface of the housing 21 is sealed.

As a material of the pump body 31, for example, cast iron may be used.

(Pump Rotor 35)

The pump rotor 35 is mounted at an end of the shaft 41 on the front side (the +Z side) and accommodated in the pump chamber 33. The pump rotor 35 has an inner rotor 37 mounted to the shaft 41 and an outer rotor 38 surrounding the outer side of the inner rotor 37 in the radial direction.

The inner rotor 37 is an annular gear having teeth on an outer surface in the radial direction. The inner rotor 37 is fixed to the shaft 41 by an end of the shaft 41 on the front side (the +Z side) being pressed into the inner rotor. The inner rotor 37 rotates along the shaft 41 in the direction around the axis (the θ direction).

The outer rotor 38 is an annular gear surrounding the outer side of the inner rotor 37 in the radial direction and having teeth on an inner surface in the radial direction. The outer rotor 38 is rotatably accommodated in the pump chamber 33. The outer rotor 38 has an inner housing chamber (not illustrated) that houses the inner rotor 37 formed in, for example, a star shape. The number of internal teeth of the outer rotor 38 is greater than the number of external teeth of the inner rotor 37.

The inner rotor 37 and the outer rotor 38 mesh with each other, and when the shaft 41 causes the inner rotor 37 to rotate, the outer rotor 38 rotates according to the rotation of the inner rotor 37. As the inner rotor 37 and the outer rotor 38 rotate together, the volume of the space formed between the inner rotor 37 and the outer rotor 38 changes according to a rotation position thereof. The pump rotor 35 sucks oil from an intake port 82, which will be described below, by using the change in the volume, pressurizes the suctioned oil, and discharges the oil from a discharge port 83. In the present example embodiment, a region of which a volume increases (i.e., a region in which oil is suctioned) in the space between the inner rotor 37 and the outer rotor 38 is referred to as a negative pressure region.

<Pump Cover Portion 80>

The pump cover portion 80 is positioned on the front side (the +Z side) of the pump body 31. The pump cover portion 80 has a pump cover body 81, the intake port 82, the discharge port 83, the intake opening 84, the first discharge opening 85, the second discharge opening 86, a first oil passage 87, a second oil passage 88, and a sealing member 89.

(Pump Cover Body 81)

FIG. 3 is a partial cross-sectional view illustrating main portions of the oil pump device according to the present example embodiment.

The pump cover body 81 is mounted on the front side (the +Z side) of the pump body 31. The pump cover body 81 is normally formed of a metal such as an aluminum alloy, has a high heat capacity and a large surface area, and thus exhibits a high heat radiation effect. In addition, since oil having a certain temperature (e.g., 120° C.) or lower flows inside the pump cover body 81, a temperature rise in the pump cover body 81 can be mitigated. The pump cover body 81 has a first base 81 a, a side surface part 81 b, a second base 81 c, a third base 81 d, an extension 81 e, a recess 81 f, a through hole 81 g, and a hole 81 h.

The first base 81 a has a disk shape extending in the radial direction and closes the opening of the recess 33, which serves as a pump chamber, on the front side (the +Z side). In addition, the through hole 81 g into which the shaft 41 is inserted is provided in the first base 81 a in the axial direction. The through hole 81 g is concentric with and has the same diameter as the through hole 31 a provided in the pump body 31. That is, when the pump cover body 81 is mounted on the front side (the +Z side) of the pump body 31, the through hole 81 g becomes a through hole that is continuous with the through hole 31 a in the axial direction.

The side surface part 81 b extends from the end of the first base 81 a on the −X side (the left side of the drawing) to the rear side (the −Z side) and comes in contact with the side surface at the end of the protrusion 31 c on the −X side (the left side of the drawing). The side surface part 81 b covers the part of the pump body 31 on the front side (the +Z side) from the side surface thereof.

The second base 81 c has an outer diameter that is smaller than that of the first base 81 a and is provided on the front side (the +Z side) of the first base 81 a. The third base 81 d has an outer diameter that is smaller than that of the second base 81 c and is provided on the front side (the +Z side) of the second base 81 c.

The second base 81 c and the third base 81 d have the hole 81 h for a discharge opening having a diameter larger than that of the through hole 81 g.

The extension 81 e extends from the first base 81 a to the +X side (the right side of the drawing) in the radial direction. The recess 81 f is provided on the +X side (the right side of the drawing) of the extension 81 e in the radial direction. The recess 81 f is open to the rear side (the −Z side), and a solenoid valve 91, which will be described below, is installed in this portion. In addition, the second discharge opening 86 is provided on the front side of the recess 81 f.

(Intake Port 82 and Discharge Port 83)

FIG. 4 is a perspective view illustrating the inside of the pump cover portion 80 taken when the pump cover body 81 of FIG. 3 is removed along the line A-A. In addition, FIG. 5 is a plan view illustrating the inside of the pump cover portion 80 taken when the pump cover body 81 of FIG. 3 is removed along the line B-B.

The intake port 82 is a crescent-shaped groove as illustrated in FIG. 4 or FIG. 5. The intake port 82 communicates with the pump rotor 35 in conjunction with an increase in a volume of the space formed between the inner rotor 37 and the outer rotor according to the increase of the volume. Likewise, the discharge port 83 is also a crescent-shaped groove as illustrated in FIG. 4 or FIG. 5. The discharge port 83 communicates with the pump rotor 35 in conjunction with a decrease in the volume of the space formed between the inner rotor 37 and the outer rotor 38 according to the decrease of the volume.

(Intake Opening 84, First Discharge Opening 85, and Second Discharge Opening 86)

The intake opening 84 penetrates the first base 81 a and the second base 81 c from the intake port 82, extends in a direction parallel to the axial direction, and reaches a surface of the second base 81 c as illustrated in FIG. 3. The intake opening 84 has a crescent shape when viewed from the front side (the +Z side) as illustrated in FIG. 1. The intake opening 84 is connected to an oil pan (not illustrated) through a circulation pipe, which is not illustrated, and oil stored in the oil pan is suctioned into the intake opening 84.

The first discharge opening 85 has a hollow cylindrical shape and is provided to be fitted into the hole 81 h. A tip of the shaft 41 pierces the bottom of the first discharge opening 85 and a part thereof protrudes to the front side (the +Z side). The first discharge opening 85 is connected to a main flow path (not illustrated) of a control valve, and the main flow path is connected to, for example, a clutch side. That is, oil discharged from the first discharge opening 85 is supplied to the clutch side.

The second discharge opening 86 extends from the inside of the recess 81 f provided in the extension 81 e to the front side (the +Z side) in the axial direction and reaches the surface of the extension 81 e on the front side (the +Z side). The second discharge opening 86 has a circular shape when viewed from the front side (the +Z side) as illustrated in FIG. 1. The second discharge opening 86 is connected to the oil pan (not illustrated). That is, oil emitted from the second discharge opening 86 is sent to the oil pan.

(First Oil Passage 87 and Second Oil Passage 88)

The end of the first oil passage 87 on the rear side (the −Z side) is connected to the discharge port 83 and the end thereof on the front side (the +Z side) is connected to the first discharge opening 85 as illustrated in FIG. 3. The second oil passage 88 extends inside the extension 81 e in the radial direction. The −X-side end of the second oil passage 88 is connected to the first oil passage 87, and the +X-side end thereof is connected to an outer circumferential part of the extension 81 e. That is, the second oil passage 88 of the present example embodiment is provided to branch off from the first oil passage 87. The +X-side end of the second oil passage 88 is sealed by the sealing member 89 such as a screw.

The intake opening 84 and the first discharge opening 85 are connected to the pump chamber 33 via the intake port 82 and the discharge port 83 respectively. Accordingly, the configuration makes suction of oil to the pump chamber 33 and discharge of the oil from the pump chamber 33 possible.

<Solenoid 90>

The solenoid 90 is disposed on the +X side of the housing 21 in the radial direction and is supported by the extension 81 e of the pump cover body 81. The solenoid 90 has a solenoid valve 91 and a pressure sensor 92. The solenoid valve 91 adjusts an amount of oil circulating inside the pump cover body 81. The pressure sensor 92 detects the pressure of oil circulating inside the pump cover body 81.

(Solenoid Valve 91)

The solenoid valve 91 has an intake opening through which oil is suctioned, a discharge opening through which oil is discharged, and an electromagnetic valve that adjusts an amount of oil. The solenoid valve 91 has a cylindrical shape and is disposed such that a length direction thereof is parallel to the central axis J. The end of the solenoid valve 91 on the front side (the +Z side) is fitted to the recess 81 f provided in the extension 81 e, and thus the discharge opening of the solenoid valve 91 is linked with the second discharge opening 86. Meanwhile, the intake opening of the solenoid valve 91 is connected to a branch oil passage 88 a branching from the second oil passage 88 as illustrated in FIG. 4 and FIG. 5. Accordingly, some or most of oil flowing in the first oil passage 87 flows from the second oil passage 88 to the solenoid valve 91 side and is discharged from the second discharge opening 86 to the outside. The amount of oil flowing to the solenoid valve 91 side is adjusted by the electromagnetic valve inside the solenoid valve 91.

(Pressure Sensor 92)

The pressure sensor 92 is also disposed on the +X side of the housing 21 (the right side of the drawing) in the radial direction and is supported by the extension 81 e of the pump cover body 81, similarly to the solenoid valve 91. However, the pressure sensor 92 is disposed on the +Y side of the solenoid valve 91 (the front side of the drawing) as illustrated in FIG. 4. The pressure sensor 92 has a rod shape and is disposed such that a length direction thereof is parallel to the central axis J. The end 92 a of the pressure sensor 92 on the front side (the +Z side) is fixed to the extension 81 e as illustrated in FIG. 5. The end 92 a is connected to a branch oil passage 88 b branching from the second oil passage 88. Accordingly, the pressure of oil flowing in the second oil passage 88 is measured by the pressure sensor 92.

<Action of Present Example Embodiment> (Flow of Oil)

Next, a flow of oil will be described with reference to FIG. 6.

FIG. 6 is a partial cross-sectional view illustrating a flow of oil inside the oil pump.

First, oil stored in the oil pan (not illustrated) enters the inside of the oil pump device 10 from the intake opening 84 through a circulation pipe, which is not illustrated, due to negative pressure generated by the inner rotor 37 rotating inside the pump chamber 33 of the oil pump device 10, and reaches the intake port 82 (flow path I). The oil is suctioned from the intake port 82 into the pump chamber 33 (flow path II), is fed by pressure from the pump chamber 33 to the discharge port 83 (flow path III), and then flows from the discharge port 83 to the first oil passage 87. Some or most of the oil that has flowed to the first oil passage 87 flows inside the first oil passage 87 to the front side (the +Z side) (flow path IV), and then is discharged from the first discharge opening 85 (flow path V). The oil discharged from the first discharge opening 85 flows through the main flow path of the control valve and is supplied, for example, to the clutch side. The supplied oil generates oil pressure, then returns, and is stored in the oil pan again.

Although the oil flow described so far is similar to the oil flow of the conventional oil pumps, there may be a case in which operations in a half-clutch state become unstable due to an oil vibration caused by a pressure variation of oil inside the pump chamber 33 in the oil flow. In order to solve the inconvenience, increasing the number of pump rotation operations in the pump chamber 33, for example, from 400 to 1200 is considered. However, if the number of rotations is simply raised, the flow amount of oil discharged from the discharge opening increases, and thus pressure in the half-clutch state will not be maintained.

For this reason, in the present example embodiment, the second discharge opening 86 is further provided in addition to the first discharge opening 85 on the path of oil pressure-fed from the discharge port 83 to the outside of the oil pump device, and the solenoid valve 91 is disposed between the discharge port 83 and the second discharge opening 86. Specifically, the second oil passage 88 branching from the first oil passage 87 is provided, the intake opening of the solenoid valve 91 is connected to the second oil passage 88 side, and the discharge opening of the solenoid valve 91 is linked with the second discharge opening 86. Accordingly, some or most of the flow amount of oil to be supplied to an oil supply destination (e.g., the clutch) from the first discharge opening 85 can be caused to flow to the solenoid valve 91. Specifically, some or most of oil that has flowed to the first oil passage 87 flows to the +X side (the right side of the drawing) inside the second oil passage 88 (flow path VI) and is discharged from the second discharge opening 86 via the solenoid valve 91 (flow path VII). The oil discharged from the second discharge opening 86 is supplied to the oil pan and stored in the oil pan again.

The amount of oil diverted from the first oil passage 87 to the second oil passage 88 can be adjusted according to an open/closed state of the electromagnetic valve inside the solenoid valve 91.

Therefore, even when the number of rotations of the oil pump device is increased, for example, from 400 to 1200 in a case in which a pressurized oil supply destination is the clutch, an increase in the flow amount of the oil supplied to the clutch can be curbed, and by increasing the frequency of the oil vibration, the pressure in the half-clutch state can be maintained while preventing clutch judder in the half-clutch state.

(Operation of Oil Pump Device)

Next, an operation performed when the oil pump device 10 works will be described with reference to FIG. 2.

In the oil pump device 10 of the present example embodiment, first, power is supplied to the control circuit part 60 from an external power supply connected via the power supply opening 63. Accordingly, a driving current is supplied to the coil 53 of the stator 50 from the control circuit part 60 via the busbar 64, a terminal, which is not illustrated, and the busbar assembly 56. When the driving current is supplied to the coil 53, a magnetic field is generated, and then the magnetic field causes the rotor core 43 and the rotor magnet 44 of the rotor 40 to rotate along with the shaft 41. In this manner, the oil pump device 10 gains a rotational driving force.

The driving current supplied to the coil 53 of the stator 50 is controlled by the control circuit 62 and the like of the control circuit part 60. Specifically, the control circuit part 60 detects a rotation position of the rotor 40 by the rotation sensor, which is not illustrated, detecting a change in a magnetic flux of a sensor magnet (not illustrated). The control circuit 62 of the control circuit part 60 outputs a motor driving signal according to the rotation position of the rotor 40 and controls the driving current supplied to the coil 53 of the stator 50. In this manner, driving of the oil pump device 10 of the present example embodiment is controlled.

When power is supplied from the control circuit part 60 to the coil 53, the power is applied to the coil 53, thus a rotating magnetic field is generated, and thereby the rotor core 43 and the rotor magnet 44 rotate. The rotation of the rotor 40 is transmitted to the inner rotor 37 of the pump rotor 35 via the shaft 41, and thus the inner rotor 37 rotates. Accordingly, negative pressure is generated in the pump chamber 33 which faces the intake port 82.

<Effects of Present Example Embodiment>

(1) In order to solve the inconvenience that operations become unstable in the half-clutch state resulting from the oil vibration caused by the pressure variation of the oil pump, increasing the number of rotations of the pump rotor, for example, from 400 to 1200 is considered. However, if the number of rotations is simply raised, the flow amount of oil increases, and thus pressure in the half-clutch state will not be maintained.

Thus, the above-described problem can be solved by disposing a solenoid valve on the path of oil pressure-fed from the discharge port 83 to the discharge opening in the present example embodiment. Specifically, the second discharge opening 86 is further provided in addition to the first discharge opening 85 as discharge openings, and the solenoid valve 91 is disposed between the discharge port 83 and the second discharge opening 86. More specifically, the second oil passage 88 branching from the first oil passage 87 is provided, the intake opening of the solenoid valve 91 is connected to the second oil passage 88 side, and the discharge opening of the solenoid valve 91 is linked with the second discharge opening 86.

Accordingly, some or most of the flow amount of oil to be supplied to an oil supply destination (e.g., the clutch) from the first discharge opening 85 can be caused to flow to the solenoid valve 91 side. The amount of oil flowing on the flow path can be adjusted with the solenoid valve 91, and as a result, the amount of oil supplied, for example, from the first discharge opening 85 to the clutch can be adjusted. Therefore, even when the number of rotations of the oil pump device is increased, for example, from 400 to 1200, an increase in the flow amount of the oil supplied to the clutch can be curbed, and by increasing the frequency of the oil vibration, the pressure in the half-clutch state can be maintained while preventing clutch judder in the half-clutch state.

(2) In the present example embodiment, the solenoid valve 91 is disposed close to the pump main body via the pump cover body 81. Thus, the whole system can be miniaturized and the structure can be simplified in comparison to a case in which a solenoid valve is disposed close to the clutch that is a pressurized oil supply destination on the control valve side. More specifically, an oil passage for the solenoid valve does not need to be provided on the control valve side, and work of incorporating a solenoid valve to the control valve side is unnecessary. In addition, a connector for power supply to the solenoid valve and a harness do not need to be further provided, and work of connecting the solenoid valve to the connector is unnecessary.

(3) In the present example embodiment, the motor 20, the pump 30, and the control circuit part 60 can be provided in a row in the axial direction and have a compact cylindrical shape, and thus can be universally used in various transmissions.

(4) In the present example embodiment, since the intake opening 84, the first discharge opening 85, and the second discharge opening 86 are provided in the pump cover body 81 that is a separate body from the pump body 31, there is no need to apply complex processing and manufacture a discharge opening and an intake opening in the pump body 31 that requires a certain degree of rigidity.

(5) In the present example embodiment, since the oil pump is integrated with the solenoid valve 91 via the pump cover body 81, the number of components and mounting man-hours can be more reduced in comparison to, for example, a case in which the solenoid valve 91 is mounted on an outer side of the pump cover body 81 via another component.

(6) In the present example embodiment, since the first oil passage 87 and the second oil passage 88 are provided in the pump cover body 81, the oil passage connecting the oil pump and the solenoid valve 91 can be further shortened in comparison to, for example, a case in which the solenoid valve 91 is mounted to an outer side of the pump cover body 81 via another component. Accordingly, miniaturization of the oil pump device 10 can be promoted.

(7) In the present example embodiment, since the second oil passage 88 and the second discharge opening 86 are provided in the extension 81 e of the pump cover body 81, the solenoid valve 91 can be integrally connected to the oil pump via the extension 81 e. Thus, the number of components and mounting man-hours can be more reduced in comparison to, for example, a case in which the solenoid valve is mounted on an outer side of the pump cover via another component.

(8) In the present example embodiment, since the solenoid valve is disposed such that a length direction thereof is parallel to the axial direction, miniaturization of the pump device can be promoted.

(9) In the present example embodiment, since the supply destination of pressurized oil is the clutch, the inconvenience that operations become unstable in the half-clutch state can be solved.

(10) In the present example embodiment, since the second oil passage 88 can be processed as a through hole of the pump cover body 81, the processing position can be easily confirmed in comparison to a case in which the second oil passage 88 is not a through hole. Due to this configuration, processing man-hours for the pump cover body 81 can be reduced.

Second Example Embodiment

Next, an oil pump device according to a second example embodiment of the present disclosure will be described. In the first example embodiment, the example in which the second oil passage 88 branches from the first oil passage 87 has been described. On the other hand, a second oil passage does not branch from a first oil passage in the oil pump device of the present example embodiment. Differences from the first example embodiment will be mainly described below. With respect to the oil pump device according to the present example embodiment, the same reference numerals are given to the same configuration components as the oil pump device according to the first example embodiment, and description thereof will be omitted.

FIG. 7 is a partial cross-sectional view illustrating main portions of the oil pump device according to the second example embodiment.

While the discharge port 83 and the first discharge opening 85 are connected by a first oil passage 97, a second oil passage 98 extending to the +X side (the right side of the drawing) from the discharge port 83 is provided in the oil pump device according to the present example embodiment. The intake opening of the solenoid valve 91 is connected to the second oil passage 98, and the discharge opening of the solenoid valve 91 is linked with the second discharge opening 86. That is, the second oil passage 98 does not branch from the middle of the first oil passage 97 but is directly connected to the discharge port 83.

Accordingly, some or most of the flow amount of oil to be supplied from the discharge port 83 to a pressurized oil supply destination (e.g., a clutch) can be allowed to escape to the solenoid valve 91 side via the second oil passage 98.

Thus, even when the number of rotations of the oil pump device is increased, for example, from 400 to 1200 in a case in which a pressurized oil supply destination is the clutch, an increase in the flow amount of the oil supplied to the clutch can be curbed, and by increasing the frequency of the oil vibration, the pressure in the half-clutch state can be maintained while preventing clutch judder in the half-clutch state.

<Effects of Present Example Embodiment>

(1) In the present example embodiment, while the discharge port 83 and the first discharge opening 85 are connected by the first oil passage 97, the second oil passage 98 extending to the +X side (the right side of the drawing) from the discharge port 83 is provided. The intake opening of the solenoid valve 91 is connected to the second oil passage 98, and the discharge opening of the solenoid valve 91 is linked with the second discharge opening 86.

Accordingly, some or most of the flow amount of oil to be supplied from the first discharge opening 85 to a pressurized oil supply destination (e.g., the clutch) can be allowed to flow to the solenoid valve 91 side. The solenoid valve 91 can help adjustment of an amount of oil flowing in the flow path, and as a result, an amount of oil to be supplied from the first discharge opening 85 to, for example, the clutch can be adjusted. Therefore, even if the number of rotations of the oil pump device is increased, for example, from 400 to 1200, an increase in the flow amount of the oil supplied to the clutch can be curbed, and by increasing the frequency of the oil vibration, the pressure in the half-clutch state can be maintained while preventing clutch judder in the half-clutch state.

In addition, the effects described in (2) to (10) for the first example embodiment can also be exhibited in the present example embodiment.

Although several example embodiments of the present disclosure have been described above, the example embodiments are merely examples and do not intend to limit the scope of the disclosure. The example embodiments can be implemented in other various modes and can be subjected to various omissions, replacements, and modifications in a scope not departing from the gist of the disclosure. The example embodiments and modifications belong to the disclosure described in the claims and equivalents thereof as well as the scope and gist of the disclosure.

Although the solenoid valve 91 is disposed between the discharge port 83 and the second discharge opening 86 in the first and second example embodiments, for example, the solenoid valve 91 may be disposed between the discharge port 83 and the first discharge opening 85.

In addition, lengths, shapes, and the like of the intake opening 84, the first discharge opening 85, and the second discharge opening 86, shapes, width and height dimensions, and the like of the intake port 82 and the discharge port 83, and lengths, shapes, and the like of the first oil passages 87 and 97 and the second oil passages 88 and 98 of the first and second example embodiments can be appropriately changed as needed.

While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims. 

1-13. (canceled) 14: An oil pump device, comprising: a motor including: a shaft that is disposed along a central axis; a rotor that rotates around the shaft; a stator that is disposed to face the rotor; and a housing that accommodates the rotor and the stator; and a pump including: a pump rotor that rotates along with the shaft and sucks and discharges oil; and a pump housing that includes an accommodation portion that accommodates the pump rotor; wherein the pump housing includes: an intake opening through which the oil is suctioned; a discharge opening through which the oil is discharged; and a solenoid valve between the discharge opening and the accommodation portion. 15: The oil pump device according to claim 14, wherein the solenoid valve opens and closes a flow path between the discharge opening and the accommodation portion. 16: The oil pump device according to claim 14, wherein the discharge opening includes a first discharge opening and a second discharge opening; and the solenoid valve is between either of the first discharge opening or the second discharge opening and the accommodation portion. 17: The oil pump device according to claim 16, wherein the solenoid valve is between the accommodation portion and the second discharge opening. 18: The oil pump device according to claim 14, wherein the pump housing includes: a pump body that accommodates the pump rotor and includes a recess including a side wall surface and a bottom positioned on the other side of the motor in an axial direction and an opening on one side of the motor in the axial direction; and a pump cover that closes the opening and includes the discharge opening and the intake opening. 19: The oil pump device according to claim 18, wherein the pump cover is on one side of the pump in the axial direction; and an oil pump main body and the solenoid valve are fixed to the pump cover. 20: The oil pump device according to claim 18, wherein the solenoid valve includes a second intake opening through which the oil is suctioned and a third discharge opening through which the oil is discharged to an oil storage side; the pump cover includes a first oil passage that is the flow path between the first discharge opening and the accommodation portion and a second oil passage that is the flow path between the second discharge opening and the accommodation portion; and a portion of the second oil passage is connected to the second intake opening of the solenoid valve and the second discharge opening is connected to the third discharge opening of the solenoid valve. 21: The oil pump device according to claim 18, wherein the solenoid valve includes a second intake opening through which the oil is suctioned and a third discharge opening through which the oil is discharged to the oil storage side; the pump cover includes a first oil passage that is the flow path between the first discharge opening and the accommodation portion and a second oil passage that is the flow path that branches from the first oil passage and is connected to the second discharge opening; and a portion of the second oil passage is connected to the second intake opening of the solenoid valve and the second discharge opening of the pump cover is connected to the third discharge opening of the solenoid valve. 22: The oil pump device according to claim 20, wherein the pump cover includes an extension that extends outward in a radial direction from an outer circumference of the motor and includes the second oil passage and the second discharge opening in the extension. 23: The oil pump device according to claim 20, wherein the pump cover includes an extension that extends outward in a radial direction from an outer circumference of the pump body and includes the second oil passage and the second discharge opening in the extension. 24: The oil pump device according to claim 14, wherein the solenoid valve is disposed such that a length direction of the solenoid valve is parallel or substantially parallel to the axial direction. 25: The oil pump device according to claim 16, wherein a supply destination of the oil from the first discharge opening is a clutch. 26: The oil pump device according to claim 20, wherein the second oil passage extends in a direction perpendicular or substantially perpendicular to the axial direction and penetrates the pump cover to an outer circumferential portion, and a seal is located at an end of the second oil passage connected to the outer circumferential portion of the pump cover. 27: The oil pump device according to claim 21, wherein the pump cover includes an extension that extends outward in a radial direction from an outer circumference of the motor and includes the second oil passage and the second discharge opening in the extension. 28: The oil pump device according to claim 21, wherein the pump cover includes an extension that extends outward in a radial direction from an outer circumference of the pump body and includes the second oil passage and the second discharge opening in the extension. 29: The oil pump device according to claim 21, wherein the second oil passage extends in a direction perpendicular or substantially perpendicular to the axial direction and penetrates the pump cover to an outer circumferential portion, and a sealing member is at an end of the second oil passage connected to the outer circumferential port of the pump cover. 